Smart compression therapy for venous ulcers: The effect of the positioning of the sensors and the posture of the leg on applied pressures

To treat venous ulcers of the lower leg with compression therapy, the right external pressure needs to be applied with the use of compression bandage or hosiery in order to improve the venous return. These days, it is difficult for health practitioners and doctors to know for sure if the right pressure has actually been achieved according to the recommendations, if a pressure gradient is indeed obtained and if these pressure levels are maintained in function of the time. To get a better view on this distribution and magnitude of the pressure, this paper has started with the examination of 16 different positions of the force sensor that will be used to measure the applied pressures. Measurements are done with one type of stocking on one plastic and one human leg. Four different heights along the lower leg have been defined and for every height, four different directions are being used to study the pressures more precisely (anterior, posterior, medial, lateral). Further, this paper has also studied the effect of 3 different movements of the lower leg, namely sitting, standing and lying down. On which height the sensor is placed at and whether the sensor is placed upon bone, fat or muscle is of importance. The placement of the force sensor, and thus the natural shape and consistency of the leg, has an important influence on the measured pressure. The anterior side will show the best results and highest pressures. Also, the movement of the lower leg indeed showed to have an effect on pressure. The standing and sitting position show higher pressures compared to when lying down. The quantization and mapping of the pressure is absolutely necessary for the further improvement of smart compression stockings and the treatment of venous ulcers.  

Key words: compression therapy, venous ulcers, force sensors, pressure gradient